In power equipment, a power electronic conversion apparatus is often employed to convert power from alternating current into direct current, or from direct current into direct current, or from direct current into alternating current, or from alternating current of the same frequency into alternating current, or from alternating current of variable frequency into alternating current. For example, in the branch power transmission lines (within a range of 2.4 kV-69 kV medium voltage) of the power system, the aforementioned power electronic conversion apparatus is used to realize the output of the power.
Multiple high and low voltage conversion systems of high frequency isolation transformation are generally cascaded on the existing medium-voltage branch power transmission lines, and the high and low voltage conversion systems include a high and low voltage conversion circuit and an apparatus for installing the aforementioned high and low voltage conversion circuit. The apparatus includes a closed housing; a low-voltage circuit and a high-voltage circuit of the high and low voltage conversion circuit are respectively installed at the front and rear end of the housing and are separated by an insulating barrier; an insulation layer is clad on the inner wall of the housing at one end of the high-voltage circuit, and terminals for cascading the high and low voltage conversion systems are introduced out of a left side wall and a right side wall.
However, the existing high and low voltage conversion system of this kind is additionally provided with a water-cooling device for cooling the high and low voltage conversion system.